Javascript: submit form, set value, disable button

Question

My form has two submit buttons and I need to know which was used to submit the form. I'd like submission of the form to be disabled once it has been submitted in order to avoid double-submissions, and I'd like to use inline Javascript for that.

I can submit the form and disable a button, but the value of the button is not set since it has been disabled and I need that value to be set so I know which button was used to submit the form.

The submit button has id="submit_button" and I'm using this on the form tag:

onsubmit="submit_button.disabled = true; return true;"

Answer 1

1. Once you submit a form it cannot be submitted again without reloading the page.
2. To determine which button was used to submit the form, assign a name to the button, ie. <input type="submit" name="button1" value="Click me!"> . In the postback variable button1 will now only be set if this button was used.
3. The proper way to prevent double submissions is to, after processing the postback, redirect with a 303 See Other to another page, or possibly even the same page, as it will be reprocessed with a GET instead of POST as method. This way it is literally impossible to double-submit.